Spectrel

I'm planning on running at the Calabogie Motor sports Park up here in Ontario but they have a rather strict dB rating. I need to be under 100 dB near red line from 8-10 feet away. As you'll see in my sig, I have headers , cam , and no cats etc etc. And through the Borla Stingers I'd probably fail at idle.

What does everyone whos modded do to meet requirements like these? I've already accepted that the Stingers will have to go. I have a set of Z06 bi-mode mufflers kicking around, so I'll get the retrofit kit and try to pass with the valves closed. Will this be enough? If not , then whats the next step?

My car is far from setup for the track and I'm sure I'll have some more questions down the road, but this is the most pressing issue at the moment.

redtopz

High flow cats and stock catback should do it. I was at 97 dB with my stock C5Z at Laguna Seca with lg longtubes and no cats. The limit is 92 dB. Next time I installed the high flow cats and I never had a problem. They really cut down on the high frequency noise which will get you the meatball flag.

Spectrel

I'd really like to avoid HF cats if possible. Was the reading at WOT?

GettReal

I cant tell you exactly how to fix your issue as noise is what is stopping me from going to Calabogie as well. This winter Im swapping back to a plain ol OEM exhaust.

There are a couple guys I track with that went to Calabogie last season and they can tell you exactly how they measure it and what you might be able to do (Post this in the Canadian section).

With the new exhaust you might be ok.. the way you need to do their sound test is to apply the gas gradually up to their rpm (I think it was 6000) and SLOWLY back down, that will avoid the popping and harshness of the exhaust.

Steve

1BDRSK

I was at Calabogie this past September and they actually 'help' you pass. The key is to bring the revs up slowly and evenly to about 3/4 redline (above 4500 rpm) and let off slowly. The funny thing is the way they measure a stock C5 Z06 didn't pass the first time because it was cold. Warm the car up (take it for a spin down the street) then go for the test. The Stingers will have to go, you should be ok with the Ti's, they'll let you run if you're just over.
Hopefully we'll see each other at an event there next year.

shakedown067

Man I hope not.

Pumba

Why do you want to avoid the High-flow catalysts? In several tests I have seen, they only cost you one to two horsepower.

Spectrel

My exhaust setup didn't have the option for HF cats so there is no place to drop them in. It's not the end of the world but I would have to get some made up to fit my application.

Spectrel

Thanks to those to have replied and for all you fellow Canadians I look forward to seeing you all on the track next season. I have my widebody build thread in the Canadian section for anyone who's interested: http://forums.corvetteforum.com/cana...lus-intro.html

For exhaust I have decided to go with the Z06 Bi mode mufflers ( I already have them) with muffler mod, and the NPP in a box , which provides everything I need to retrofit the valve controls to my car. If that isn't enough I'll look into HF cats.

1BDRSK

Fixed it.

Spectrel

Does anyone have a link for the how to thread for installing the C6 Z mufflers on a base C6 with 2.5" X pipe?

davidfarmer

downturns "aimed" away from the meter help quite a bit as well.

Lancer033

stuff steel wool into the exhaust pipes....after you pass put the throttle to the floor and the steel wool shoots out and everything is back to normal

Armycop

Hm.. last time I was at Calabogie (Aug 09) with 3BallsRacing and some "other" group, there was a Canadian NASCAR-type car out there, wailin' away! I don't think he would have passed the db test, not with his open headers screamin' past me! Man, that thing could sing..!

bb69

I just booked the weekend of August 28 and 29 for Calabogie if you're interested. It will be two full days of open track.

Anyway, the Calabogie sound check is an interesting thing. They didn't check any of us this year because it was raining Saturday morning. As Armycop said, there were some cars that I believe belonged to the track owners that were making a lot of noise. I got nailed for noise because I was bounving off the rev limiter. Simply keeping it off the rev limited solved the problem. It was the first time in 3 years I heard them say anything. They will do what they can to get you on track.

Feel free to shoot me a PM if you want more details. I would still suggest trying to quiet down a car that was blatantly over the limit though.

Ken

Armycop

I'm running long tubes without cats and a BBoat catback, and while considerably louder than stock, I didn't get a sideways glance the whole two days. then again, neither did the race-prepped silver ZO6-R that showed up, did two laps, and then got put back on the trailer. Still, it was beauuuutiful!!

Last C5

It's not pretty, but it works. This is what I go to Laguna with.

sperkins

I need something like this for my Borla straight pipes. How did you make those and what keeps them from falling out?

Last C5

I went to the muffler shop and had four 12" pipes bent at a 45 degree angle (obviously I picked a pipe that would slide into the existing tail pipe) then I came home and slid them into each tailpipe and drilled a hole through the bottom of the tail pipe with the extension inserted, removed the extension and welded a nut over the hole so I could just slide it back in later, align it with the hole in the tail pipe and stick a short bolt in it. (See second Picture) The bolt goes through the hole in the tail pipe, through the extension, and into the welded nut. Tighten it up and you're good to go. Total install time at the track is about 5 minutes. If the Corvette Show and Shine Police catch you, you don't know me.

sperkins

Thanks Doug!